Cytomorphology of filariasis revisited. Expansion of the morphologic spectrum and coexistence with other lesions

Lymphatic filariasis and visceral leishmaniasis coinfection: A review on their epidemiology, therapeutic, and immune responses

Coinfection is less commonly observed in individuals around the world, yet it is more common than the single infection. Around 800 million people worldwide are infected with helminths as a result of various diseases. Lymphatic filariasis (LF) and visceral leishmaniasis (VL) are chronic, deadly, crippling, and debilitating neglected tropical diseases (NTDs) that are endemic in tropical and subtropical regions of the world. Due to poor hygienic conditions, poverty, and genetic predisposition, those living in endemic areas are more likely to develop both leishmaniasis and filariasis. One of the key challenges in the management of LF/VL coinfection is the development of an effective therapeutic strategy that not only treats the first episode of VL but also prevents LF. However, there is a scarcity of knowledge and data on the relationship between LF and VL coinfection. While reviewing it was apparent that only a few studies relevant to LF/VL coinfections have been reported from southeastern Spain, Sudan, and the Indian subcontinents, highlighting the need for greater research in the most affected areas. We also looked at LF and VL as a single disease and also as a coinfection. Some features of the immune response evolved in mammalian hosts against LF and VL alone or against coinfection are also discussed, including epidemiology, therapeutic regimens, and vaccines. In addition to being potentially useful in clinical research, our findings imply the need for improved diagnostic methodology and therapeutics, which could accelerate the deployment of more specific and effective diagnosis for treatments to lessen the impact of VL/LF coinfections in the population.

Cross-protective efficacy of immuno-stimulatory recombinant Brugia malayi protein HSP60 against the Leishmania donovani in BALB/c mice

Coinfection of Leishmania with bacteria, viruses, protozoans, and nematodes alter the immune system of the host, thereby influencing the disease outcomes. Here, we have determined the immunogenic property and protective efficacy of the cross-reactive molecule HSP60 of filarial parasite B. malayi against the L. donovani in BALB/c mice. Parasitological parameters results showed a significant decrease in the parasite burden (~59%; P < 0.001) and also a substantial increase in the delayed-type hypersensitivity (DTH) response (P < 0.001) in mice immunized with 10 μg of rBmHSP60. Protection against L. donovani in mice immunized with rBmHSP60 resulted from activation of the T cells, which is characterized by higher levels of nitric oxide (NO) production, enhanced cell proliferation, higher levels (expression and release) of IFN- γ, TNF- α, and IL-12, also, higher production of IgG and IgG2a antibodies. This strong Th1 immune response creates an inflammatory domain for L. donovani and protects the host from VL.

Isolated Epitrochlear Filarial Lymphadenopathy: Cytomorphological Diagnosis of an Unusual Presentation

Filariasis is a major public health problem in tropical countries like India. Despite the large number of people at risk, detection of eggs with or without larva (microfilaria) on fine-needle aspiration cytology is very unusual, especially in an uncommon site or incidentally detected in clinically unsuspected cases of filariasis with the absence of microfilariae in the peripheral blood. A 19-year-old male presented with swelling over medial aspect of left arm (just above the elbow), with no other specific signs and symptoms. Fine needle aspiration cytology revealed an adult gravid female filarial worm in a background of reactive lymphoid cells and lymphohistiocytic clusters. We report a case with elaborate fine needle aspiration cytology findings of filarial worm infestation with unusual presentation of isolated epitrochlear lymph node involvement in a clinically unsuspected case and recommend clinicians and pathologists to consider a high index of suspicion for such infections at uncommon sites especially in endemic territories, as early diagnosis and treatment prevent the more severe manifestations of disease.

Cross reactive molecules of human lymphatic filaria Brugia malayi inhibit Leishmania donovani infection in hamsters

Coinfections are common in natural populations and the outcome of their interactions depends on the immune responses of the host elicited by the parasites. Earlier we showed that immunization with BmAFII (Sephadex G-200 eluted) fraction of human lymphatic filaria Brugia malayi inhibited progression of Leishmania donovani infection in golden hamsters. In the present study we identified cross reactive molecules of B. malayi, and investigated their effect on L. donovani infection and associated immune responses in the host. The sequence alignment and sharing of linear T- and B-cell epitopes in protein molecules of B. malayi and L. donovani counterparts were studied in silico. Hamsters were immunized with robustly cross reactive SDS-PAGE resolved fractions F6 (54.2-67.8kDa) and F9 (41.3-45.0kDa) of B. malayi and subsequently inoculated with amastigotes of L. donovani intracardially. F6 inhibited (∼72%) L. donovani infection and upregulated Th1 cytokine expression, lymphoproliferation, IgG2, IgG2/3 levels and NO production, and downregulated Th2 cytokine expression. Sequences in HSP60 and EF-2 of F6 and L. donovani counterparts were conserved and B- and T-cell epitopes in the proteins shared antigenic regions. In conclusion, leishmania-cross reactive molecules of filarial parasite considerably inhibited leishmanial infection via Th1-mediated immune responses and NO production. Common B- and T-cell epitope regions in HSP60 and EF-2 of the parasites might have contributed to the inhibitory effect on the L. donovani infection. Thus, leishmania-cross reactive filarial parasite molecules may help in designing prophylactic(s) against L. donovani.

Urinary filariasis masquerading as the bladder tumor: A case report with cyto-histological correlation

Filariasis is a prevalent parasitic infection of lymphatic frequently seen in tropical countries. It has been reported in cytological samples from various sites; however, presence of microfilaria in smears from the urine sample is an uncommon finding. We describe an interesting and unusual case of elderly female who presented with achylous hematuria and an exophytic mass lesion in urinary bladder on computed tomography scan suspected of neoplastic mass lesion; however diagnosed as urinary filariasis on urine cytology and bladder biopsy.

Cytological diagnosis of bancroftian filariasis presented as a subcutaneous swelling in the cubital fossa: an unusual presentation

Filariasis is a disabling parasitic disease and the prevalence of lymphatic filariasis caused by Wuchereria bancrofti is quite high in India. However, W. bancrofti presenting as a subcutaneous swelling and a demonstration of microfilariae in cytological smears from upper extremity lesions is extremely rare. We report a case of 20-year-old male who presented with a small subcutaneous swelling near medial aspect of the left cubital fossa. The wet mount preparation showed many motile microfilariae. Cytology smears revealed a large number of sheathed microfilariae with the tail tip free of nucleus, identified as W. bancrofti without significant inflammatory cell infiltrate. Indirect ELISA was highly positive for specific recombinant W. bancrofti filarial antigen (WL-L2). The role of cytology cannot be underestimated in clinically unanticipated cases of bancroftian filariasis, especially with the amicrofilaremic state. Filariasis should always be considered in the differential diagnosis during cytological evaluation of any swelling, especially in endemic areas.

Role of fine needle aspiration cytology in diagnosing filarial arm cysts

Filariasis is prevalent in tropical and subtropical areas and is endemic in regions of India. Lymphatic filariasis in India is caused mainly by two species of nematodes: Wuchereria bancrofti and Brugia malayi, which invade the human lymphatic system. We report two cases of superficial cystic lesions of the upper limb revealed on fine needle aspiration (FNA) to be clinically unsuspected filariasis. Despite similar aetiologies, both cases revealed variations in aspirate nature, smear morphology and peripheral blood findings. FNA provides definitive diagnosis and is an important tool for diagnosing soft tissue swellings owing to filariasis.

Cytological diagnosis of parasites presenting as superficial nodular swelling: report of 35 cases

Parasitic infestation often present with superficial nodular swelling. Fine needle aspiration cytology plays an important role in prompt diagnosis of the disease. To study the role of FNAC in the diagnosis of parasites presenting as skin or subcutaneous nodules. Total 361 cases of superficial swellings at various sites were subjected to fine needle aspiration cytology. Out of the 361 cases, 35 cases were diagnosed as suggestive of parasitic infestation. These 35 cases form the study group. In 14 cases out of 35 cases, a definitive diagnosis of parasitic infestation was made as parasite or fragments of parasite were seen in the aspirate. In 21 cases, neither parasite nor fragments could be identified on the aspirates and a diagnosis of parasitic inflammation was suggested on the basis of other cytomorphological findings. In 17 of these cases, a biopsy correlation was available, which revealed definitive parasite in 8 cases and the remaining 9 were reported as suggestive of parasitic cyst. The cytological diagnosis was confirmatory in cases where the parasite fragment were identified in the smears. However, in other cases, clear aspirate, presence of eosinophils, macrophages and typical granular dirty background are the features which should prompt the cytologist to the possibility of parasitic infestation.

Respiratory Tract and Mediastinum

Normal cytology, abnormal and atypical cells, non-cellular components, and infectious cell changes are largely described together with benign, malignant, and neuroendocrine lesions regarding exfoliative and aspiration cytology of the lung. A separate section broadly addresses diagnostic findings and differential diagnoses in bronchoalveolar washings.

The section ‘Fine needle aspiration biopsy of mediastinal disorders’ covers in particular biopsy techniques, accuracy of liquid-based cytology, and the complex lesions of the thymus gland. Cytodiagnostic algorithms of the major benign and malignant pulmonary and mediastinal lesions and their respective differential diagnoses are additionally presented in synoptic setups.

Significance of incidental detection of filariasis on aspiration smears: a case series

Filariasis is a major public health problem in tropical and subtropical countries including India. Although there are reports of incidentally diagnosed cases of lymphatic filariasis in the existing literature, the significance of this finding needs to be summarised in one place. The association of filariasis with neoplasms is still debatable. For this series, cases diagnosed as filariasis on aspiration cytology (with or without coexistent pathology) over a period of 1 year were retrieved. The cases with a clinical suspicion of filariasis were excluded. Hence, five cases with incidental diagnosis of filariasis on aspiration cytology were included. The site of aspiration included one case each of thyroid, breast, bone marrow, cervical lymph node, and subcutaneous nodule. Of these, three cases showed microfilariae, one showed only adult female worm while one showed both microfilariae and adult worm. Two cases did not show any inflammatory response while three cases showed a variable inflammatory reaction. Only one case (thyroid aspirate) had a coexistent pathology (colloid goitre). Filariasis may be detected in a clinically unsuspected case, especially in an endemic zone. The spectrum of host response may vary from no reaction to a marked inflammatory response. The entire spectrum of changes should be kept in mind while practicing cytopathology in an endemic area. In such situations, a high index of suspicion and careful screening of cytology smears are keys to a correct diagnosis. At the same time, keen search for a coexisting pathology, benign or malignant, is also mandatory.

Influence of Brugia malayi life stages and BmAFII fraction on experimental Leishmania donovani infection in hamsters

The influence of live Brugia malayi parasites and a Sephadex G-200 fraction of the adult parasite extract (BmAFII) on the progression of Leishmania donovani infection was studied. Inbred hamsters were first infected with B. malayi infective 3rd stage larvae (L3), adult worms or microfilariae (mf), and then with L. donovani amastigotes (Ld), or vice versa or received both the infections simultaneously; a group of animals were first immunized with BmAFII and then infected with Ld. L. donovani parasite burden was determined between 17 and 19 days post amastigote challenge (p.a.c.) and, in case of immunized animals, between 32 and 35 days p.a.c also. Nitric oxide (NO) release from peritoneal macrophages and cellular proliferative responses of lymphnode cells were assessed in BmAFII-immunized animals given leishmania infection or no infection. Leishmanial parasite burden was significantly reduced in animals exposed to filarial L3 before amastigote inoculation and in animals given filarial adult worms after or together with amastigotes. Prior immunization of leishmania-infected animals with BmAFII also reduced the leishmanial parasite burden (17-19 days p.a.c.: >90%; 32-35 days p.a.c.: 60%). These animals showed upregulation of NO release and cellular proliferative responses to promastigote antigen or BmAFII stimulation in vitro. The findings show, for the first time, that B. malayi L3/adult worms or immunization with BmAFII inhibits progression of L. donovani infection in hamsters and this is associated with upregulation of NO and lymphocyte proliferative responses indicating that Th1 response might be responsible for this.

Sclerosing lobular hyperplasia of the breast: fine-needle aspiration cytology findings--a case report

Sclerosing lobular hyperplasia (SLH) is an uncommon benign lesion seen in the juvenile breast. It presents as a palpable, firm, circumscribed nodular lump in the breast of a young woman. Histologically, it is characterised by prominent lobular hyperplasia and sclerosis of the intralobular connective tissue. We discuss the cytomorphology and differential diagnosis. A 16-yr-old female patient presented with a painless, firm, nodular, mobile mass in the right breast measuring 4 x 4 cm. The clinical and radiological diagnosis was fibroadenoma. Fine-needle aspiration smears showed round to oval ductal epithelial cells in flat sheets and round clusters with an acinar arrangement. A few bare nuclei were seen dispersed in a clean background but no stroma was visualised. A combination of clinical findings, imaging, and cytological features of SLH can help to differentiate this condition from other palpable juvenile breast diseases.

Perineal nodule due to enterobiasis: an aspiration cytologic diagnosis

Subcutaneous swelling due to Enterobious vermicularis infection is rare. Their presence in perineal subcutaneous tissue is unusual and a clinical curiosity. A case of subcutaneous nodule in the perineum due to E. vermicularis infection diagnosed on fine-needle aspiration is described. Tissue reaction was granulomatous with neutrophils and eosinophils. Lack of familiarity with the morphology of parasites or its eggs, degeneration, and inadequate sampling may make the diagnosis difficult. This case report provides the morphologic clues to cytopathologists toward rendering a diagnosis and alerts them to the possibility of parasitic infection in unusual locations.